1. Field of the Invention
This invention relates in general to medical procedures and equipment. In particular, the invention relates to an improved catheter and a method of inserting a catheter into a selected artery.
2. Description of the Prior Art
Catheters are used in the performance of medical procedures, such as coronary angiography and angioplasty. The purpose of angioplasty is to widen the lumen of a coronary artery which has become partially blocked by a stenotic lesion. A stenotic lesion is an abnormal narrowing of an artery due to injury or disease.
The angioplasty procedure involves the introduction of a catheter system into the aorta, by way of the femoral artery, under local anesthesia. The catheter system includes a guiding catheter and a dilating catheter. The distal end of the guiding catheter is inserted into the opening of a selected coronary artery.
The dilating catheter is then passed through the guiding catheter into the coronary artery. The distal end of the dilating catheter is positioned within the stenotic lesion in the coronary artery. A balloon on the end of the dilating catheter is then inflated with a fluid. The balloon forces the blockage open and enlarges the lumen of the artery.
A problem sometimes develops during the procedure, if the dilating catheter has to pass through a tight stenosis or blockage. The reaction force on the catheter assembly may cause the end of the guiding catheter to slip out of the coronary opening. This results in an unstable condition, in which it is much more difficult to pass the dilating catheter through the stenotic lesion.
One possible solution to this problem is to provide an inflatable balloon near the distal end of the guiding catheter. After the guiding catheter has been inserted into the opening of the coronary artery, the balloon is inflated. The balloon engages the inner surface of the coronary artery, and stablizes the guiding catheter. The dilating catheter can then be passed through the guiding catheter and through the stenotic lesion, without forcing the end of the guiding catheter out of the coronary lumen. A catheter assembly and method of this type is described in a co-owned and co-pending patent application.